It is frequently necessary to carefully inspect rotating objects, such as those found in the automotive industry; e.g., tires, engine components, transmissions components, differential gears, or even parts moved along the assembly line. Another object requiring careful inspection is helicopter transmission gears because they are subject to demanding torque and load requirements that lead to fatigue failure. Additionally, the meshing of the transmission gears is the primary source of cabin noise and often necessitates personnel to wear hearing protection. It is desired to analyze these meshing gears so as to reduce the attendant noise thereof and to define specific events in the failure process to better understand and predict failures. Gear mesh diagnostics includes a diagnostic system to warn of conditions leading to failure.
Many different approaches have been proposed in the past for providing efficient and accurate systems for inspecting gears and one such system is described in U.S. Pat. No. 5,373,735 ('735) which is herein incorporated by reference. The '735 patent discloses a gear testing method and apparatus for inspecting the contact area between selected tooth surfaces of a gear member, such as a spiral bevel or hypoid gear. The gear testing includes a coating device for coating a selected portion of the gear member with the material to form a footprint and a strobing device which is adjusted to illuminate and inspect one of the gears while the gears are still in rotation. It is beneficial to inspect a gear while it is being rotated because it may reveal a flaw thereof, such as a hairline crack, that may only be manifested while the gear of interest is rotating and meshing with a complementary tooth of a similarly rotating gear. It is desired that methods and an apparatus for performing gear inspection be provided without the need of any coating device so as to eliminate the attendant drawbacks thereof.
Accordingly, it is a primary object of the present invention to provide for methods and an apparatus for inspecting a gear that has no need for any coating device and performs such inspection without any need to contact a rotating and meshing gear.
It is a further object of the present invention to provide for an imaging system used to acquire temporal data in the form of images to construct a history of the possible failures of the rotating and contacting gears over time.
It is another object of the present invention to provide for images of a meshing gear operating under torque and load conditions so as to allow the ability to track a crack or pit developed in a gear and measure the progression or expansion of the crack or pit over time.
Further, it is an object of the present invention to provide for an imaging system used for gear inspection having a digitized output that can be immediately analyzed and thereby provide valuable feedback at the time of any possible failure.
Moreover, it is the object of the present invention to provide an automated and computer controlled imaging system used for gear inspection that can be continuously run to acquire multiple images without any need for any supervision of the imaging system.